Motor drive



May 22, 1923.

1,456,082 H. E. WARREN MOTOR DRIVE Original Filed Sept. l, 1920 PatentedMay 22, 1923.

STATES PATENT OFFICE.

HENRY E. WARREN, F ASHLAND, MASSACHUSETTS, ASSIGNOR TO WARREN CLOCKCOMPANY, A CORPORATION OF MAINE.

MOTOR DRIVE.

Original application led September 1, 1920, Serial No. 407,487. Dividedand this application led .Tanuary 17, 1922. Serial No. 530,005.

To all lwhom it may concern.'

Be it known that I, HENRY E. WARREN, a citizen of the United States,residing at Ashland, in the county of Middlesex, State of Massachusetts,have invented certain new and useful Improvements in Motor Drives(division of Serial No. 407,487 filed. September 1, 1920), of which thefollowmg 1s a s eciication.

his invention relates to a motor drive, and more particularly to a drivecomprising means for producing mechanical motion, such as a motor, andtransmitting mechanism adapted to modify the character of the motionproduced by the motor at the point where the power is to be used.

My invention finds particular application to that class of drives usedfor transmitting motion to the hands of synchronous motor drivensecondary clocks. The main object of my invention is to provide a deviceof the character indicated, inexpensive to manufacture, and exceedinglycompact. Another object of my invention is to provide a device formodifying the speed of the motor which is easily adjustable fordifferent directions of rotation and for different shafts alignments andwhich may be quickly and easily replaced.

Other objects and advantages, consisting in various improvements andmodifications pertaining to motor drives, will hereinafter be more fullydescribed and claimed.

The construction and mode of operation of my invention may be understoodfrom the description taken in connection with the'accompanying drawing,in which Figure 1 is a sectional view showing the various elements ofboth the motor and the transmitting mechanism; and Fig. 2 is an outlineside view showing more clearly the relation between the motor and theenclosing case of the drive.

Referring now more in detail to the drawing, in which like referencecharacters refer to like parts throughout, my invention may be used inconjunction with a motor 1, which I show in this case as a synchronous.selfstarting motor described in Letters Patent 1,283,432, granted in myname and assigned to the same assignee as the present application. It isof course to be understood that although I show my invention inconnection with this type of motor, it may be used with all sizes ortypes of machinery or motors, such as non-electrical motors or primemovers. The particular motor shown comprises a series of stationarylaminations forming the stator or field 2 and a plurality of shadingcoils 3. The field 2 carries a coil 4 which serves as the excitingmeans. I have shown a rotor 5 located in the space between the polesofthe iield 2 and adapted to be rotated upon energization of the coil 4as is well understood. By the aid of my invention the speed of thisrotor 5 is reduced, and the power is made available at the power shaft 6which carries in this instance a driving pinion 7. rlhis driving pinionmay operate the load for which the apparatus is designed; in thisinstance, the hands of an electrically actuated clock may be driven. Inother instances, however, much greater forces may be efficientlytransmitted by appropriate design of the transmission.

Between the shaft 31 of rotor 5 and the power shaft 6 there areinterposed a plurality or" gears designated in general by the numeral 8.These gears modify the speed of the rotor 5, and illustrate but onemeans for accomplishing this result. All of the gears are totallyenclosed in a gear case 9 and its cover 10. yIhe particular constructionof this gearing will be described later on. The gear case 9 has acylindrical portion 11 closed at the end by the wall 12. Thiscylindrical portion totally encloses the rotor 5 as shown and is held tothe stator, in this case, 4frictionally held within the inner peripheryof the stationary portion of the motor. This method of holding theentire gear case to the stator of the motor permits the motor 1 to bereversed in relation to the gear case. That is, the side of the motormarked A may be made to take the position now held by side 13, and viceversa. rllhis reversal causes a reversal of the direction of rotation ofthe rotor, and a reversible drive is obtained. This feature alsofacilitates the replacing of gear .units for the purpose of repair. Itwill be understood that the units comprising the casings 9 and 10 andthe containing parts may be made up for different gear ratios withoutinterfering in any way with their interchangeability.

The cover 10 for the gear case 9 is held in place by any appropriatemeans. In this instance I provide for this purpose interengagingcylindrical portions 13 and 14 carried respectively 'by the gear case 9and the cover 10. These two cylindrical portions 13 and 14'may be heldtogether simply by friction, by mak'ing their engaging surfaces of thep-roper size. In this way it is possible to slip the cover 1() over thegear case 9 with great facility. The power shaft 6 extends through thecover 10, and in order that the entire case be oil-tight, I provide a)acking 28 for this shaft. The packingr mayI lie either felt or cork,and is appropriately held in place between the threaded cap 30 and themouth-shaped proje: tion 29 formed on the cover 10. It is to be notedthat the axis of shaft 6, while parallel with that of rotor 5, isdisplaced therefrom. It is thus possible, by an angular adjustment ofthe entire gear case to compensate for the varying sizes of gears withwhich pinion 7 may mesh. This angular adjustment is convenientlyaccomplished in the present instance by rotating part 11 of the casewithin the inner periphery of the stationary member 2.

The elements making up the gearing 8 will now be described. In order toreduce the friction as much as possible and to provide sufficientlubrication appropriate means are used to supply the oil to the bearingsurfaces of these elements. These means provide a capillary spa-ce orpassageway between an oil well and the engaging sliding surfaces of thebearing and the shaft journaled therein. Oil from the well is carried,by capillary attraction, to the sliding snrfaces. I shall now describehow I provide the capillary space. As shown clearly in F ig. 1, thebearing supports for the various shafts designated by 6, 15, 16, and 17which serve to support' the gears, comprise a pair of metallic membersor plates 18, separated by capillary space 19. This separation may beproduced in any well known way; in this instance 'by the use of aplurality of small projections 20 punched in one of the two plates 18;appropriate fastening means such as screws 21 are provided for holdingthe two metallic members 18 together. In the drawing, for the sake ofclarity, I have shown members 18 separated much farther than isnecessary in actual practice. For keeping the two pairs of metallic.members 18 spaced lthe proper distance apart, I provide appropriatemeans such as the spacers 22 riveted to the inside plates, as clearlyshown in Fig. 1. In one or the other of the two plates 18 there isprovided a bearing for each of the shafts used in the transmittingtrain. The plates 18 dip into the oil 23 which is appropriately held ina portion of the gear case 9, which serves as a well therefor. The levelof this oil 23 is considerably below the level of any of the shaftssupported in the plates 18 and the oil gets to these shafts by means ofthe capillary attraction through the capillary space 19. It is to benoted also that each of the two plates 18 serves to limit the thrust orsidewise movement of those shafts journaled solely in the other of saidpair of plates. The entire structure comprising the bearing plates 18and reduction gearing 8 is held to the gear case 9 against a flatannular surface 24 provided thereon by means of appropriate fastenerssuch as the screws 25.

The shaft 17 which carries the gear 26 meshing with the gear 27 servingto drive the power shaft 6 extends through both of the left-hand plates18, as shown, so that the cover l0 may be removed without the necessityof disturbing the remainder of the mechanism. The )ower shaft 6 isjournaled in the outer of the two left-hand bearing plates 18, as isclearly1 shown, and its axial movement' is prevented in one directionby4 the inner plate and in the other direction by the inner surface ofthe gear case cover. The lubrication provided by the means described hasbeen found to be ample.

In the present instance the rotor 5 is held in the field produced by thestator of the motor 1 by magnetic attraction. That is to say, the rotorshaft 31 has a longitudinal axial movement and is held in operativeposition meshing with the appropriate gear only when the motor is inoperation. To provide a good bearing surfafe for the shaft 31 of therotor I use a member 32, appropriately held to one of the metallicmembers or plates 18, such as by riveting, as shown, and having an outerbearing )ortion 33 accommodating the shaft 31. onneoting the slidingsurfaces ofthe bearing and shaft at the portion 33 is an annularcapillary space 34 which connects with the capillary space formedbetween the members 18. This capillary space is obtained by providing anaperture within the member 32 of the proper size, through which theshaft 31 extends. Thus al capillary space extends from the oil 23,between the two members 18, through capillary space 34, and to thesliding surfaces at the end of member 33. To provide a suiliciently longbearing for the shaft 31 at its left-hand end I use a bushing 35fastened to the inner of the two metallic plates 18. By means of thisconstruction the shaft 31 is extremely well supported near each end.Then the rotor 5 is in its inoperative position, the shaft 31 may slideto the left and disengage the driving pinion 36 from its gear. However,when a current passes through the coil 12 there is a m netic attractionsufficient to cause the shit-It 31 to move to the right, so that therotor 5 assumes a central position with respect to the eld structure 2,and pinion 36 is reengaged with the first of the train of reductiongears 8.

It is thus seen that I provide an extremely inexpensive and compactdevice for modifying the speed of a rotor shaft, and for properlylubricating the moving parts. lVhile I have shown in the accompanyingillustration but one embodiment of my device, I do not wish to belimited thereto but aim to cover in the appended claims allmodifications falling fairly within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,- y l. A motor drive comprising a motor having a stationarypart and a rotating element, a gear case enclosing the rotating elementof i the motor and held within the inner periphery of the stationarypart of said motor, a cover for said case having an aperture, a powershaft extending through said aperture, and means supported in said casefor transmitting motion from the rotating element to the power shaft.

2. A motor drive comprising a m'otor having a stationary part and arotating element, a gear case totally enclosing the rotating element ofthe motor, that portion of which encloses the rotating element beingheld within the inner periphery of the stationary part of said motor, insuch a way as to make the angular relation between the gear case and themotor adjustable, a cover for said case, and a power shaft extendingfrom the gear case parallel with the shaft of the. rotating element buthaving its axis displaced from the axis of said rotating element.

3. Afmotor drive comprising an electric motor having a stator elementand a rotating element, a gear case enclosing and supportinoI therotating element of said motor, adapted to be inserted and held withinthe inner periphery of said motor from either side in a position tobring the rotor element Within the operative inuence of said statorelement, a power shaft extending through a wall of said casing and speedchanging gearing supported in said case ior transmitting motion from therotating element to said power shaft.

4. An interchangeable speed changing unit for a motor, comprising anoil-tight casing provided with a cylindrical projection, a plurality ofintermeshing gears supported in said casing7 a rotor for the motorcontained in the cylindrical portion of said casing and supported indriving relation with one of said gears and a power sha-ft in drivingconnection with another of said gears extending through an aperture insaid casing.

5. A motor drive comprising a motor having a stationary part and arotating element, an oil-tight gear case totally enclosing the rotatingelement of the motor, that portion of which encloses the rotatingelement being held within the inner periphery of the stationary part ofsaid motor in such a way as to make the angular relation between thegear case and the motor adjustable, a horizontally disposed power shaftextending from the gear case parallel with the shaft of the rotatingelement but having its axis displaced from the axis of said rotatingelement, speed changing means in said casing for transmitting motionfrom the rotating element to said power shaft, a lubricant in the bottomof said casing, and vertically disposed partitions in said casing forrotatively ysupporting' the rotating elements contained therein adaptedtooconvey lubricant to said supports by capillary action irrespective ofthe angular adjustment of said casing.

In witness whereof, I have hereunto set my hand this 27th day ofDecember, 1921.

HENRY E. WARREN.

